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Commit a86ee03c authored by Ira Snyder's avatar Ira Snyder Committed by Dan Williams
Browse files

dma: add support for scatterlist to scatterlist copy 



This adds support for scatterlist to scatterlist DMA transfers. A
similar interface is exposed by the fsldma driver (through the DMA_SLAVE
API) and by the ste_dma40 driver (through an exported function).

This patch paves the way for making this type of copy operation a part
of the generic DMAEngine API. Futher patches will add support in
individual drivers.

Signed-off-by: default avatarIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent cc60f887

drivers/dma/dmaengine.c

+2 −0
Original line number Diff line number Diff line
@@ -690,6 +690,8 @@ int dma_async_device_register(struct dma_device *device) 
		!device->device_prep_dma_memset);

	BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&

		!device->device_prep_dma_interrupt);

	BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&

		!device->device_prep_dma_sg);

	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&

		!device->device_prep_slave_sg);

	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&

include/linux/dmaengine.h

+6 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ enum dma_transaction_type { 
	DMA_PQ_VAL,

	DMA_MEMSET,

	DMA_INTERRUPT,

	DMA_SG,

	DMA_PRIVATE,

	DMA_ASYNC_TX,

	DMA_SLAVE,
@@ -473,6 +474,11 @@ struct dma_device { 
		unsigned long flags);

	struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(

		struct dma_chan *chan, unsigned long flags);

	struct dma_async_tx_descriptor *(*device_prep_dma_sg)(

		struct dma_chan *chan,

		struct scatterlist *dst_sg, unsigned int dst_nents,

		struct scatterlist *src_sg, unsigned int src_nents,

		unsigned long flags);



	struct dma_async_tx_descriptor *(*device_prep_slave_sg)(

		struct dma_chan *chan, struct scatterlist *sgl,